1. Field
The present invention relates to a manufacturing method for SiO2—TiO2 based glass, to a manufacturing method for a plate-shaped member made of SiO2—TiO2 based glass, to a manufacturing device, and to a manufacturing device for SiO2—TiO2 based glass.
2. Description of Related Art
In a photolithographic process, exposure processing is performed in which exposure light is irradiated upon a photo-mask, and a photosensitive substrate is exposed to the exposure light from the photo-mask. This type of photo-mask is obtained by forming a predetermined mask pattern upon a photo-mask substrate.
In recent years, the increase in size of photosensitive substrates has progressed remarkably, and, along with this, the size of photo-masks has also increased; for example, for an exposure device for liquid crystal panels from the eighth generation onward, a large-sized photo-mask is used in which one side is longer than 1.2 m. A photo-mask substrate that is used for a photo-mask having this type of large area can be manufactured by taking, as source material, an SiO2 glass ingot that is formed as a circular cylinder that is produced by a vapor deposition method such as the direct method, and by press-molding this material so as to make a flat plate-shaped member (see Japanese Laid-Open Patent Publication 2002-53330).